


Love and Hate

by eikuuhyo



Category: Undertale (Video Game)
Genre: Character Death, Yandere and older Frisk
Language: English
Status: In-Progress
Published: 2015-10-17
Updated: 2015-10-26
Packaged: 2018-04-26 17:45:20
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 2
Words: 3,855
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5014075
Author URL: https://archiveofourown.org/users/eikuuhyo/pseuds/eikuuhyo
Summary: <blockquote class="userstuff">
              <p>Dedicated to all the players of Undertale who thought that Genocide Sans was hot as hell. General pronouns used for Frisk since I can see them being male or female. Somewhat older and yandere Frisk who is infatuated with Sans for all the wrong reasons.</p><p>Obviously will contain major spoilers.</p>
            </blockquote>





	1. Love

Sans had been watching the human ever since they had stepped out of the Ruins. There was a part of him that hoped that this human would be the one that would break the cycle... The one who would be the key to breaking the shield keeping monsters from going above ground into the human world. The one who would finally bring a new age to monsters.

Yet, those hopes were shattered within minutes. The human—was it even correct to call it that anymore, he wondered—began slaughtering every monster in sight. Gentle, meek monsters vanished without a trace as the human's knife dug into their flesh. Even then, Sans decided to at least attempt at trying to stop the human from doing so.

Those actions were fruitless, though. Sans cursed himself over and over for not stopping them sooner... before they had killed his only brother in this world. He wondered countless times when he could've stepped into to stop the massacre. Papyrus, Undyne, Mettaton... At this rate, there was the chance that the lady behind the door at the ruins had been killed as well.

That was why when the human had reached the Capital, Sans finally stepped in. A chill ran down his spine as he told the human about what LV and EXP were, since during his speech, they didn't even bat an eye. They continued to stare at him with those emotionless eyes, the brutal knife still in hand. He had no choice by then.

The battle began.

It wasn't even a fair battle, and Sans knew it. He pulled all the tricks he could from his sleeve to attack the human, grabbing hold of the human's body with his—his brother Papyrus'—blue magic, slamming them against the stone walls of the castle in hopes that he would end their life so they need not suffer long. The human was resilient too, as they continued to try and attack with their knife, shoving their mouth full of god-knows-what they've picked up along the way.

But within minutes, the battle was over. The human laid motionless on the ground, their weapon lying across the floor, and blood splattered everywhere from Sans' attacks. Sans panted as he finally released the blue magic from the human. Were they dead? Was it finally over?

He quietly walked over to the body and then—

 

 

Sans was back in the same corridor as before.

He was giving the speech about LV and EXP to the human devoid of any emotion on their face... for the second time? The skeleton could've sworn that he had already done this once, however now wasn't the time for such doubts. A bony hand was lifted up, and the battle against the human began.

All of the human's slashes were dodged, more laser shots rained down upon them, and eventually, the human collapsed.

Blood trickled across the floor, even reaching Sans, who was gasping for breath.

The human had fought viciously and it was getting to the point that he himself was running out of options when—

 

 

Sans was back in the same corridor as before.

Again.

Something was amiss as Sans caught himself doing the same speech for the third time, though the words kept falling out of his mouth as if they were programmed to do so. The battle commenced like before and as the human went down—

 

 

Sans was back in the same corridor as before.

Battle commences.

Human dies.

 

 

Sans was back in the same corridor as before.

Battle commences—

 

 

It wouldn't be until the twentieth battle or so that a sense of dread creeps upon Sans. He could swear that the human had died under his hand twenty times now, yet at the end of every battle, the two of them would back here at the exact same place. The exact same words being repeated. The only difference between the battles being how the human was starting to learn Sans' attacks and dodging them more efficiently.

After the fiftieth battle, Sans had had enough.

With blue magic raging in the room, he slammed the human's body against the wall and yelled, "What are you doing, kid!? What is the meaning of this!?" To which, the only reply he got back was an eerie smile. This was the first time the human had shown any emotion, and it spooked Sans to his bones.

A few coughs were made by the human as their body was dropped back down to the floor, blood splattering the stone ground each time. Even Sans could tell that they were on their last amount of health, and only one more strike was needed to finish them off.

That was when the human spoke. "... _Meaning_...?"

Their voice was barely a whisper, yet Sans swore their voice echoed across the corridor.

"There IS a meaning to this, Sans..."

The human stumbled to their feet again, picking up the knife they had dropped earlier.

"Don't you get it...? I could've ended this battle much sooner... but I didn't want to."

Eyes that had been devoid of emotion now had a fire behind them. Of what, Sans did not want to know.

"I didn't want this battle to end... Of all the monsters I've fought here... you're the only one that interests me. You're the only one, who can stand up against me..." the human muttered, their smile getting wider. "Your attacks. Your voice. Your magic... All of it... _excites_ me."

Another chill ran down Sans' spine at those words. The words the human was saying made sense, yet Sans did not want to acknowledge what they meant by them.

"Sans... Oh, I love you so much... If only I had fought you sooner..." they continued to say before cutting themselves off. It seemed they were thinking, grimacing only once in a while from the pain shooting through their body. "Sooner... Hehe... Right..."

"...Kid?"

"Hehe... Hehehehehehe! That's right! Sooner! Had I fought you sooner... Nnngh... I wouldn't have needed to kill so many monsters...! They would still be alive, oblivious of everything...!"

The hollow laugh rang through the corridor, the tone filled with insanity. Sans, realizing that there is nothing more he can do to change the human's mind, raised his hand and performed one last attack. Four of the goat skulls appeared, firing their lasers upon the still cackling human and piercing its fragile body.

More blood spilled onto the floor as the human fell to their knees, but not before locking eyes with Sans one last time.

"...Sans... See you... soon..."

And then, everything went black.

 

 

 

  
It had been a cold morning outside of Snowdin like always. Fresh snow continued to fall from the sky—if it could even be called a sky, since the land of monsters was underground—and Sans pulled his jacket's hoodie over his head as he stepped out of he and his brother's house. Papyrus had already left early in the morning, something about adjusting the traps he had setup for humans, which was ridiculous in itself, since no human had set foot in these lands for ages now.

Then again, there was the conversation he and that mysterious voice beyond the door to the Ruins he had had recently... She had asked him to promise to protect a "human" who may step through those doors. There was something about the tone of her voice that had made Sans agree to it, though hesitant he felt about it. It had been a week since then, and if there truly was a human about to come through those doors, then it'd be best if he were ready to greet them there.

Soft crunches echoed on the ground as Sans languidly walked through the usual forest, through the "gate" made by Papyrus to try and stop humans from passing. He never had the heart to tell his brother that it wouldn't work since the bars were so wide. Still, Sans can't help but smile and shake his head as he keeps walking, the thought of his brother so fanatic about catching humans too endearing for him. Such thoughts are cut short though when Sans notices someone up ahead on the trail. Could the human have exited the Ruins already?

Sans looked up and gave a smile, about to greet them when—

"...Hi, Sans."

The human greeted themselves to him. And in their hand, was a knife gleaming in the darkness. An eerie smile was plastered on said human's face as they raised the weapon and whispered, "...I'm back."

The moment those words left the human's mouth, it hit Sans like a ton of bricks. All the memories until now came racing back to the skeleton monster: every murder, every death, every kill... Sans fell to his knees with a gasp as he remembered everything that had happened—could happen again, in the future.

He doesn't know how the human has done it, but they have managed to reset the timeline and returned to the very beginning before everything began. He clearly remembers his brother being well and not dead by the hands of the very human standing ahead of him. There were jokes, laughter, wonderful times that had passed—

There was a flash of blue and the human jumped back, avoiding the laser strike that has singed the ground.

Sans' left eye is burning a vibrant blue and his smile is more tense as he brings out his magical weapon. The human before him smiles even wider. A hint of red seems can be seen in those eyes as they give a heated sigh.

"...Yes, this is much better. Much more intense," the human laughs, "You see, Sans, if you don't kill me... and keep killing me, I WILL destroy everything this time."  
Sans grits his teeth at those words for he knows it's true. He is the only one standing between that human—that MONSTER—and all lives in the underground world. If he were to fall, that means everyone will be lost... including his beloved brother.

"...Why?" the skeleton was barely able to whisper out. "Why are you doing this, kid?"

Another, eerie laugh.

"Oh Sans... I told you last time. I LOVE you. I love you to death. I love your voiced. I love your attacks. I love how you kill me. I love the utter HATE that you direct at me... There is nothing more in this world I love more... than you."

The human paused for an instant, twirling the knife in hand. They wipe off what seems to be dust clinging to it and stares right at the shell-shocked Sans.

"...It'll be just you and me. To the end of time. Kill or be killed. And if a day ever comes where I succeed in killing you... well, I guess I'll have to start over from the beginning again."

"...Heh, there's no way to convince you otherwise, huh?" Sans muttered back, his smile looking more wry.

A happy nod is returned back and all Sans can do is give a heavy sigh. His one eye, burning blue locks with the human's as he raises his hand in preparation for battle. The human also takes hold of the weapon and their smile disappears.

"Fine. I'll play by your rules, you dirty brother killer."

The human laughs once more. "Oh, Sans... I haven't killed him yet in this world. Now try and kill me so that I never do."

 

Bad End


	2. The Cycle

**Summary for the Chapter:**

> I had a dream about this story one night, and what happened in it gave me inspiration to continue it. Same cautions will apply as before. More chapters will be coming!

Ever since the human had reset the timeline back to the very beginning and Sans was dragged into a demented cycle of death and rebirth, Sans' life entered a routine. Every morning after Papyrus set out to check on his human-catching traps, Sans headed out of Snowdin and into the woods. There, the human would be waiting for him, toying with the wicked blade in hand, and they would do battle. Since there has been no major change in the monster world for the time being, it was obvious who had won every day. Each morning resulted in another reset, and the cycle would continue.

Every victory was another day that Sans would be relieved. It meant that the monsters, especially his brother, would go unharmed, and all would be well. Then again, every victory also entailed him having to go to bed that night, worried sick to his stomach on whether he would be victorious the next day. Though Sans woke up in the morning with his magical powers restored, it did not mean that the mental toll on him was relieved.

The repeat of such fatigue eventually led to him having to end a battle prematurely one day. Sans had the human pinned against the doors to the Ruins that morning, his magic crushing their small throat. He could only imagine how much pain he must've been inflicting on said human, but the only thing he saw in their eyes was the glimmer of joy. It wouldn't have been exaggerating to even call it a form of pleasure as well as the human felt their life flicker before their eyes once again. Sans could've ended it there, had it not been for a piercing headache that struck him.

"Nngh....!" Sans groans as he clasped his head, falling to one knee in the process. His magic also dissipates and the human falls to the ground, coughing and wheezing for air. (No, this can't be now!) the skeleton panics. The human has grown strong over the repeated battles, and such a slip up is all they need for them to kill him. Sans struggles to get back to his feet, seeing that the human has also gotten back up and managed to get their weapon back. However, the best he can do is teeter towards the nearest tree and brace against it for support. The worst case scenario is playing through Sans' head as the human approaches him. The pain in his skull is even stronger now. He can't fight back the groans though he knows that he must continue fighting.

When the human finally draws near the tree that Sans is leaning against, he braces for the worst... though no matter how much he waits, the painful blow never comes. To his surprise, he opens one eye and finds the human looking at him, curiously and with a hint of what could be called concern.  
"...What's the matter, Sans?" the human asks. 

"I-It's nothing, kid..." Sans barely is able of muttering out. "C'mon... I-I can keep going."

There is the usual flash of blue which catches the human off guard and and the magic slams them into a nearby tree, resulting in a pained grunt. The air of battle returns to the snowy forest—though it only lasts for an instant. Sans' vision suddenly goes blurry with a mighty pain striking his skull, and the last thing he sees as his consciousness fades is the human looking at him with eyes wide open.

 

* * *

  
——Red.  
That is all Sans sees as he notices himself standing in the midst of a crimson lake. He wonders what he is doing there since his last memory was of him facing the human in their daily duel. His mind is a haze as he tries to think more. After multiple failed attempts to figure out what's going on, Sans decides to take a step in some direction in search of answers. His footing had been solid until then, yet when he makes that first step, he suddenly feels something grab at it. Shocked, Sans looks down and finds a horrific sight.

Under the red water were countless bodies—bodies of monsters that he recognized. Mutilated. All with contorted expressions. And amongst them, was his brother Papryus... the one grasping his foot. Sans jaw locks tight at that sight, trying desperately not to scream at seeing his brother broken, mangled, and what looked like blood dripping from his empty eye sockets.

(Monsters don't bleed. This can't be real! This can't be happening!)

But seeing the sight of Papyrus in such a state shakes up Sans more than anything he's experienced in his life. He can't get himself to shake free of that grasp either, since that is still his brother under the water. However, he wishes that he had when Papyrus' jaw opens and a voice that is barely a whisper echoes.

"...Why...?"

Suddenly, light returns to all the monsters. Their mouths open in the most grotesque of manner as they begin to mutter.

"Why... didn't you... help us...?"

"You could've... stopped them..."

"Why didn't you... do better..."

"You knew... How could you...?"

The combined weight of all the monsters drags Sans into the water, bloody hands grabbing at the panicking skeleton. His eyes lock with those of his brother's as he utters the words that shatters Sans' heart.

"—We're dead, because of _you_."  
  


* * *

 

  
Sans jumps awake, clasping both his hands over his mouth to prevent the scream from leaving it. He can feel sweat pouring down his skull as he frantically looks around in confusion. The last thing Sans remembers is him facing the human in their daily duel, the massive pain in his skull, and... darkness. He looks around and finds that he's lying in his own bed, in his own room. When had he come back? How did he come back? And most importantly, what of the human?

"Oh hey, you're up," a familiar voice echoes from towards the bedroom door. "I grabbed some... nice cream? You want some?"

A quick glance in that direction shows the human standing at the open doorway, licking one of what seems to be two servings of nicecream, the local favorite. Nowhere in their hand is the usual knife as they casually come strolling into the room. Sans is about to instinctively use his magic to restrain said human, but it is the sight of Papyrus peeking into his room that stops him.

"Brother, you're awake! Thank goodness, you worried me sick!" Papyrus exclaims as he rushes in past the human and smothers Sans in a tight hug. It's minutes before his brother lets him go, and when he does, Sans doesn't even need to ask for an explanation of what's going on.

"Oh! And don't worry about that human! They were the one that carried you back here, so they're good! Even I, the Great Papryus, knows when a human is friend or foe."

It takes some effort for Sans to not blurt out that his brother is wrong about this one, yet he bites his non-existing tongue to remain quiet. He does mumble out an apology to Papyrus for worrying him instead.

"Well, I should get back to work! Never know when another human may pass through, after all!" And just like that, Papyrus was gone as quickly as he had come, leaving Sans and the human alone in the room once again.

Everything seemed... bizarre to Sans. First, he had seen the human worry about him before he blacked out—which seems genuine now, if they had carried him back to he and his brother's house in Snowdin. Second, though Sans had feared the worst, it seems the human had not killed anyone during all this. Papyrus was obviously alive and well, and the human made no attempt to hurt him in the process. Third and most of all, the human just handed him some nicecream and was now sitting on the side of the bed, licking away at their cold treat as if everything was well... which it wasn't.

"...What're you doing, kid?" Sans couldn't help but ask.

"Hm?" the human responds while cocking their head to the side. "What do you mean?"

"You had every chance to kill me. And everyone else. So... why am I, and they still alive?"

Sans' words seems to make the human think. They look off towards the corner of the room and sway their feet while seated on the edge of the bed, as if lost in thought. After minutes of contemplation, they munch the last bit of nicecream in their hand before licking their fingers clean and shrugging. "...Dunno. Yeah, it would've been easy to kill you then and there, but... it didn't seem right. There's no fun in killing you if you're not up to your game."

A logical answer considering why the human is so obsessed with him. Still, that didn't answer the second part of Sans' question.

"Not that I'm not thankful for it, but then why not everyone else?"

"Eh. They're what keeps you going and fighting me. That's why I reset everything, remember? I don't really care about killing them."

Sans watches as the human hops off his bed and walks over to him. They bring their face close to his—uncomfortably close, that is—and checks him over. A smile eventually returns to their expression as they step back.

"Well, looks like you're getting a little better. We'll postpone the fight until tomorrow. Sound good? No point in fighting you if you're not bringing your A-game," the human says while they begin to exit the bedroom. "Rest up, okay? I'll see you back in the forest tomorrow morning."

And like that, the human was gone.

It would be tens of minutes later that Sans would finally feel at ease and lays back down. He kept wondering if this was some kind of trickery, if the human would suddenly appear and attack him out of the blue... even though that never happened. No screams were coming from outside the house, which meant the human wasn't attacking the villagers either. There was no knowing why they were having a sudden change of heart, but that didn't change the matters at hand.

Just as the human had said, everything will go back to the usual tomorrow.

Sans pulled his bed's sheets over his head and closed his eyes. He had to rest. He got lucky this time with the human and their finicky personality, though he was certain there would be no repeat of this. Sleep did not come easily for him, nor was his slumber anymore restful than the previous one since it was once again riddled with nightmares.

  
When the next day came, Sans and the human resumed their battle as always. The human was back to their usual self, desperately dodging every attack thrown at them, while smiling the way they usually did. The same could be said for Sans as well, for the day's rest had allowed him to regain control over his magic and to battle the human with the same ferver as before. At the end of it all, the human laid dead in their own blood, and Sans returned back to his brother and his home to wait for the next day when everything would be reset again.

The accursed cycle would begin once again... or so Sans thought, until one morning he woke and went downstairs to the kitchen to find the human there, their head on the table and fast asleep.

Whatever the reason may be, the cycle had changed. And Sans did not like it.


End file.
